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A closer look at my pistons...

Posted by davecarama , 02-22-2012 · 1,584 views

Pistons... Ahh, Pistons...

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I started wiping them down last night. In this photo, the one on the far left is still dirty, as in untouched. They really were not that bad, all things considered, and cleaned up pretty easy with some paper towels and maybe some goo-gone.

I do however think I found the real reason my motor was smoking "Spy Hunter" style. The oil rings were collapsed in the little groove. WAY too much carbon build up to allow them to move freely. And that was on all all four.

What does that mean? Look closer here:
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This dirty piston, you can clearly see the rings (left to right: Compression, scraper, oil ring, oil ring spacer, oil ring). The compression and scraper rings were free moving and springing out of the groove. That is good.
The oil rings were tight and flush with the piston (the zig-zag looking thingy is the spacer that is sandwiched between the oil rings). They did not rotate AT ALL. That is bad.

Here is a closer look, This is after I used my finger nail to "free" them from being stuck:
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Before I freed them, you almost couldn't see that gap (right oil ring towards the top) and it was flush with the piston as in fully compressed and stuck like that (unlike now where you can see the space at the bottom where it expanded out of the groove).

What made them stick like that?
Carbon build up... or gunky old oil that gets crusty, cooked-on, and clogs stuff. Here is what the rings should NOT look like (carbon build-up):
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No... They should NOT be black. They should be shiny bright metal color. These will be going into the trash.

The bamboo kabob skewer was my cleaning tool for in-between the ring grooves. It worked VERY well, so much so that I used it on the faces of the pistons too. I used this instead of wire brushes because the pistons are made out of aluminum and scratch very easilly. The bamboo is softer than the piston, so it was safe to use and not damage the part.

I think I am ordering parts as soon as tomorrow for my rebuild...

Dave

- EDIT -
Just did some more scrubbing. Used a brass wire brush. MUCH better!
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Ring grooves look nice on this one (piston #1)
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And the face of course... Lookin good!
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